Modelling of detonation wave parameters, initiation and hazard of chemically active bubble systems

The detonation processes in chemically active bubble systems at high initial pressures are calculated numerically. The dependences of detonation wave velocity at sub- and supersonic regimes of propagation on molar fraction of gas in the mixture and on initial pressure have been calculated for the first time. The Chapman-Jouguet condition for supersonic bubble detonation wave is obtained. The principal possibility for a different detonation wave structure in the case of propagation in the mixture with high initial pressure and longitudinal gradient of bubble volume fraction is predicted.
The dynamics and ignition of a chemically active bubble in a field of external pressure is analyzed. It is shown, that an inert diluent addition can increase the explosion hazard of heterogeneous gas – liquid systems. Calculations demonstrate the possibility of chemically active bubble ignition on the second pulsation. It is shown, that single chemically active bubble ignition is possible also owing to a decompression impulse.
An algorithm for the calculation of thermodynamic parameters of chemically equilibrium hydrocarbon gas with soot particles has been suggested. It is shown, that soot formation can have an essential influence on the dynamics of single bubble in chemically active hydrocarbon-oxygen (organic solvent (liquid) – oxidizer (gas)) heterogeneous systems

Effect of chemically inert particles on parameters and suppression of detonation in gases

[[abstract]]An algorithm for calculating the parameters of a steady one-dimensional detonation wave in mixtures of a gas with chemically inert particles and estimating the detonation-cell size in such mixtures is proposed. The calculated detonation parameters and cell size in stoichiometric hydrogen-oxygen mixtures with W, Al2O3, and SiO2 particles are used to analyze the method of suppression of multifront gas detonation by injecting chemically inert particles ahead of the leading wave front. The ratio between the channel diameter and the detonation-cell size is used to estimate the limit of heterogeneous detonation in the mixtures considered. The minimum mass of particles and the characteristic cloud size necessary for detonation suppression are calculated. The effect of thermodynamic parameters of particles on the detonation suppression process is analyzed for the first time. Particles with a high specific heat and (if melting occurs) a high phase-transition heat are found to exert the most pronounced effect